Willow plant name ‘Preble’

ABSTRACT

A distinct female cultivar of  Salix viminalis ×( Salix sachalinensis×Salix miyabeana ) named ‘Preble’, characterized by rapid stem growth producing 29% more woody biomass than the average of three current production cultivars ( Salix×dasyclados  ‘SV1’ (unpatented),  Salix sachalinensis  ‘SX61’ (unpatented), and  Salix miyabeana  ‘SX64’ (unpatented)) when grown in the same field for the same length of time (three growing seasons after coppice) in two different trials in Constableville, N.Y. and Middlebury, Vt. ‘Preble’ can be planted from dormant stem cuttings, produces multiple stems after coppice and the stem biomass can be harvested when the plant is dormant. In the spring following harvest, the plant will re-sprout very vigorously, producing new stems that can be harvested repeatedly after two to four years of growth. ‘Preble’ displays a low incidence of rust disease and is not damaged by potato leafhoppers.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with government support under contract00-EXCA-1-0890 awarded by the U.S. Department of Agriculture/ NationalInstitute of Food and Agriculture (NIFA), under contract no.68-3A75-6-500 awarded by the U.S. Department of Agriculture, and undercontract no. DE-AC05-00OR22725 awarded by Department of Energy. Thegovernment has certain rights in this invention.

1. LATIN NAME OF THE GENUS AND SPECIES OF THE PLANT CLAIMED

Salix viminalis×(Salix sachalinensis (also known as Salix udensis)×Salixmiyabeana).

2. VARIETY DENOMINATION

Preble.

3. BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is a new and distinct cultivar known by the cultivarepithet ‘Preble’ resulting from the novel hybridization of Salixviminalis with a hybrid of Salix sachalinensis×Salix miyabeana. The newcultivar was produced through controlled willow breeding conducted bythe inventors in Syracuse, N.Y. The objective of the breeding program isto produce new willow cultivars that generate high biomass yields on avariety of sites, are resistant to diseases and pests, and possessagronomic traits suitable for mechanical planting, harvesting, andpost-harvest processing. Shrub willow is being developed as anagricultural plant that will be grown and harvested as a sustainable,renewable source of energy. Once a field planting of shrub willows isestablished, the woody stems can be harvested every two to four years,and new shoots will re-sprout the following season. Repeated harvestingevery two to four years can be sustained for at least 15 years.

2. Description of Relevant Prior Art

The invention is related to the following plant patents, all of whichare assigned to the Research Foundation of the State University of NewYork: Fast-Growing Shrub Willow Named ‘Fish Creek’, U.S. Plant Pat. No.17,710; Fast-Growing Shrub Willow Named ‘Canastota’, U.S. Plant Pat. No.17,724; Fast-Growing Shrub Willow Named ‘Millbrook’, U.S. Plant Pat. No.17,646; Fast-Growing Shrub Willow Named ‘Oneida’, U.S. Plant Pat. No.17,682; Fast-Growing Shrub Willow Named ‘Otisco’, U.S. Plant Pat. No.17,997; Fast-Growing Shrub Willow Named ‘Tully Champion’, U.S. PlantPat. No. 17,946; and Fast-Growing Shrub Willow Named ‘Owasco’, U.S.Plant Pat. No. 17,845. The cultivar of fast-growing shrub willow named‘Preble’ was produced in the same willow breeding program as were theother cultivars listed above.

This new cultivar of Salix viminalis×(Salix sachalinensis×Salixmiyabeana) was the seedling progeny of the controlled pollination of thefemale clone Salix viminalis ‘SV2’ (unpatented) by the male clone Salixsachalinensis×Salix miyabeana ‘9970-037’ (unpatented) performed inFebruary 2001 in Syracuse, N.Y. The plant has been propagated repeatedlyby stem cuttings in Syracuse, N.Y. and has been found to retain itsdistinctive characteristics through successive generations of asexualpropagation.

The parent clone Salix viminalis ‘SV2’ (unpatented) was originallytransferred in 1990 from a breeding program in Toronto, Ontario, Canadato a willow breeding program in Syracuse, N.Y. and was vegetativelypropagated from stem cuttings. The male parent, Salixsachalinensis×Salix miyabeana ‘9970-037’ (unpatented), was producedthrough controlled breeding in 1999 and is a progeny of Salixsachalinensis ‘SX61’ (unpatented) crossed with Salix miyabeana ‘SX64’(unpatented). The growth of the parent plants was characterized innursery plantings in Tully, N.Y. The male clone Salixsachalinensis×Salix miyabeana ‘9970-037’ (unpatented) displayed rapidstem growth and low incidence of rust disease, so was chosen to serve asa parent in a cross with S. viminalis ‘SV2’(unpatented), which sufferedfrom susceptibility to the potato leafhopper (Empoasca fabae). Theseedlings produced by this cross (identification #01X-268) were firstestablished in a greenhouse, and then were transplanted to a field inSyracuse, N.Y. This particular individual (identification #01X-268-015)was selected from the family due to its exceptional stem height growth.

The new cultivar has been grown in Syracuse, N.Y. and Tully, N.Y., whichhave a normal yearly average daily temperature of 47° F., normal dailymaximum temperature in July of 82° F., normal daily minimum temperaturein January of 14° F., and average precipitation of 40 inches. The newcultivar grows from a rooted cutting to a fully mature plant ready forharvest in approximately two to four years.

This cultivar was described as displaying greater salt tolerance thanmany other Salix spp. genotypes in a paper by R. D. Hangs, J. J.Schoenau, K. C. J. Van Rees, and H. Steppuhn “Examining the salttolerance of willow (Salix spp.) bioenergy species for use onsalt-affected agricultural lands” (2011) Canadian Journal of PlantScience, 91:509-517.

4. SUMMARY OF THE INVENTION

The Salix viminalis×(Salix sachalinensis×Salix miyabeana) cultivar‘Preble’ has not been observed under all possible environmentalconditions. The phenotype may vary somewhat with variations inenvironments such as temperature, light intensity and length ofillumination, without, however, any variation in genotype. The new anddistinct cultivar presents the following traits that have beenrepeatedly observed and are determined to be the unique characteristicsof ‘Preble’. These characteristics in combination distinguish ‘Preble’as a new and distinct cultivar:

‘Preble’ has rapid growth rate, producing 29% more woody biomass thanthe average of three current production clones (Salix×dasyclados ‘SV1’(unpatented), Salix sachalinensis ‘SX61’ (unpatented) and Salixmiyabeana ‘SX64’ (unpatented)) across two sites: Constableville, N.Y.and Middlebury, Vt. At Constableville, N.Y., a site with marginal soilsand a short growing season, ‘Preble’ produced 35% greater biomass thanone of its grandparents (Salix sachalinensis ‘SX61’) (unpatented) and71% greater biomass than another of its grandparents (Salix miyabeana‘SX64’ (unpatented)), and 12% more biomass than another production clone(Salix×dasyclados ‘SV1’ (unpatented)) when grown in the same field forthe same length of time (three growing seasons after coppice). In theMiddlebury, Vt. trial, ‘Preble’ produced 18% and 27% greater biomassthan its grandparents, ‘SX61’ (unpatented) and ‘SX64’ (unpatented)respectively, and 30% greater biomass than ‘SV1’ (unpatented) when grownin the same field for three growing seasons after coppice.

‘Preble’ has resistance to potato leafhopper, which causes severestunting of growth, curling of the leaves, and overall decline in vigor(all characteristic of hopper burn) on the female parent, S. viminalis‘SV2’ (unpatented) assessed in experimental trials conducted inFredonia, N.Y. and Constableville, N.Y.

‘Preble’ has a low incidence of rust disease assessed in experimentaltrials in Fredonia, N.Y. and Constableville, N.Y.

‘Preble’ has mature leaves that are lanceolate, have an acuminate apexand a cuneate base, are typically 13-15 cm in length and 2.2-2.6 cm inwidth, lustrous, glabrous, frequently undulate along the edges, withserrate to crenate margins. The leaves of the female parent S. viminalis‘SV2’ (unpatented), by contrast, are thin and linear. The leaves of themale parent ‘9970-037’ (unpatented) are more oblong with acute apex,acute to obtuse base, typically 8.5-12.0 cm in length and 1.7-2.1 cm inwidth.

‘Preble’ has dormant vegetative buds that are lanceolate, whereas ‘SV2’(unpatented) has buds that are smaller and ovate.

5. BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying color photographs show the features of the claimedcultivar in a manner as true as is reasonably possible.

FIG. 1.1. The bark of a three-year-old portion of stem collected whiledormant.

FIG. 1.2. One-year-old portion of stem collected while dormant.

FIG. 1.3. Vegetative bud in dormancy.

FIG. 1.4. Floral bud in dormancy, prior to abscission of the bud scale.

FIG. 1.5. Floral bud in dormancy, after abscission of the bud scale.

FIG. 1.6. New shoot growth from a stem cutting rooted in potting mix ina greenhouse.

FIG. 1.7. Upper leaf surface.

FIG. 1.8. Lower leaf surface.

FIG. 1.9. Mature catkin.

FIG. 1.10. Pistil and densely pubescent floral bract.

FIG. 2.1. Mean stem biomass yield produced by ‘Preble’ over threegrowing seasons post-coppice in four eighteen-plant plots inConstableville, N.Y. harvested in December 2009.

FIG. 2.2. Mean stem biomass yield produced by ‘Preble’ over threegrowing seasons post-coppice in four eighteen-plant plots growing inMiddlebury, Vt. harvested in December 2010.

6. DETAILED BOTANICAL DESCRIPTION

The following detailed description sets forth characteristics of the newplant. The following observations and measurements describe plants grownby asexual reproduction in Geneva, N.Y. under conditions as describedhereinabove. Color references are made using The Royal HorticulturalSociety Colour Chart, Fourth Edition, 2001 (hereinafter The R.H.S.Colour Chart) of The Royal Horticultural Society of London, England,except where general terms of ordinary dictionary significance are used.

The following detailed description of the ‘Preble’ variety is based onobservations from 10 inch cuttings grown in a greenhouse in Geneva, N.Y.Cuttings were grown in ‘Cornell mix’ potting mix under natural lightfrom December 2011 to February 2012. Plants were irrigated withautomatic drip irrigation for 5 minutes each day.

-   Parentage:    -   -   Female or seed parent.—S. viminalis ‘SV2’ (unpatented).        -   Male or pollen parent: Salix sachalinensis×Salix miyabeana            ‘9970-037’ (unpatented).-   Propagation:    -   -   Type.—Stem cutting.        -   Time to rooting.—Approximately 7 days in well-watered            potting mix at 22° C.-   Precocity: Precocious — Catkins mature several days before leaves    break bud.-   Plant description: One-year-old stems are on average 1.1 cm in    diameter at a height of 1 m and an average plant produces 22 stems    in the first year after coppice. The color of one-year-old stems    observed during the winter when dormant are lustrous and    yellow-green (RHS 153B) with portions of greyed-orange (RHS N167A).    Dormant vegetative buds are greyed-orange (RHS 168A) and lanceolate.    Lenticels are slightly raised with red-pink centers rimmed by white.    The leaves are simple and alternate with pinnate venation. Petioles    are typically 6 mm in length and 1.50-1.60 mm in diameter and are    light green (RHS 143C). Stipules are rare, but when present are    typically 3-4 mm in length, narrow, and lanceolate. Immature leaves    are pubescent on the lower side and exhibit curling of the edges.    Mature leaves are lanceolate, acuminate apex, cuneate base,    typically 13-15 cm in length, 2.2-2.6 cm in width, lustrous,    glabrous, frequently undulate along the edges, with serrate to    crenate margins. The upper surface is green (RHS 143A and RHS141B),    with the lower surface only slightly lighter and more olive in hue    (RHS 139C) than the upper surface after 9 weeks of growth in a    greenhouse. The average plant height of a mature plant after three    seasons of growth is 5-6 m with average spread at the crown of    1.0-1.5 m when grown in commercial planting spacing of 0.6×0.7 m.-   Flowering description: Dormant floral buds are elongated with a    caudate apex, typically 8 mm in length, slightly raised to form a    very small acute angle with the stem, and greyed-red (RHS 180B) when    intact. During the winter dormancy period, some floral bud scales    abscise and turn greyed-purple (RHS N186C). Peduncle of catkin is    2-3 mm in length and bears four leafy bracts. Catkins are erect,    typically 3 cm in length, narrowly cylindrical, 7-8 mm in diameter    at the base, but narrowing at the tip, and are densely flowered.    Flowers have a densely pubescent sessile ovary with a medium length    style and two erect, slightly separated stigmas. Floral bract is    densely pubescent with a dark obtuse apex and a mostly pink base.-   Field growth characteristics: Determined through surveys of plants    growing in the field in Syracuse, Tully, Geneva, and Fredonia, N.Y.-   Disease resistance: Displays a low incidence of rust disease    assessed in experimental trials in Fredonia, N.Y. and    Constableville, N.Y.-   Insect resistance: Resistance to potato leafhopper, which causes    severe stunting of growth, curling of the leaves, and overall    decline in vigor (all characteristic of hopper burn) on the female    parent, S. viminalis ‘SV2’ (unpatented) assessed in experimental    trials conducted in Fredonia, N.Y. and Constableville, N.Y.-   Temperature tolerance: Stems typically do not suffer frost damage at    temperatures as low as 10° F. and may suffer only minor tip dieback    at lower temperatures.-   Seed production: ‘Preble’ produces only female flowers, so viable    seeds will only be produced after pollination by a compatible male    variety. This has not yet been observed in field trials.-   Stem features: Bark of major three-year-old stems (typically ca. 3    cm in diameter at 1 m above the ground) is greyed-green (RHS 191A)    with lighter vertical streaks. Lenticels are raised, 1-3 mm across,    and greyed-purple (RHS 184A). Except for the lenticels, the bark is    smooth and lustrous.-   Biomass yield: Mean stem biomass yield produced by ‘Preble’ over    three growing seasons post-coppice in four eighteen-plant plots in    Constableville, N.Y. harvested in December 2009 was 10.10 oven dry    Mg ha⁻¹ yr⁻¹ (FIG. 2.1) and in four 18-plant plots growing in    Middlebury, Vt. harvested in December 2010 was 14.15 oven dry Mg    ha⁻¹ yr⁻¹ (FIG. 2.2). ‘Preble’ produced 29% more woody biomass than    the average of three current production cultivars (Salix×dasyclados    ‘SV1’ (unpatented), Salix sachalinensis ‘SX61’ (unpatented) and    Salix miyabeana ‘SX64’ (unpatented)) across those two    sites—Constableville, N.Y. and Middlebury, Vt. At Constableville,    N.Y.—a site with marginal soils and a short growing season—‘Preble’    produced 35% greater biomass than one of its grandparents (Salix    sachalinensis ‘SX61’ (unpatented)) and 71% greater biomass than    another of its grandparents (Salix miyabeana ‘SX64’ (unpatented)),    and 12% more biomass than another production cultivar    (Salix×dasyclados ‘SV1’ (unpatented)) when grown in the same field    for the same length of time (three growing seasons after coppice).    In the Middlebury, Vt. trial, ‘Preble’ produced 18% and 27% greater    biomass than its grandparents, ‘SX61’ (unpatented) and ‘SX64’    (unpatented) respectively, and 30% greater biomass than ‘SV1’    (unpatented) when grown in the same field for three growing seasons    after coppice.

What is claimed is:
 1. A new and distinct variety of Salixviminalis×(Salix sachalinensis×Salix miyabeana) shrub willow plant named‘Preble’ as described and illustrated herein.